Safety bolt

ABSTRACT

A gantry crane includes a framework supporting a main girder and a pair of swingable jibs which are movable between a first position in which they form an extension of the main girder and a second, stowed position in which they are parallel to the main girder. A trolley is mounted on rails provided on the girder and jibs. A stopper arrangement includes spring-loaded bolts which are displaced into the path of the trolley upon swinging of the jibs to the stored position to prevent the trolley from running off the rails.

. United. State'sPatent f Inventor- Fredrik Munk Filed u /4.19 s

wPatented 1:1 .124),

Assignee 5 ll'lunc'k International AIS.

Priority} "NOLG, 1 967 SAITETYBOLT? tl ClaitnJ Dra'wing I-ig; g

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' 1 1114.15.73,-124,125.12;104/(consu|;ea1; I l05/(Cons11lted) [56]kel'ereneescited mm-:1) STATES PATENTS 3,244,297 4/1966 Kinkopf 212/153,249,236 5/1966 Kummerman v 212/15 3,258,129 6/1966 Munck..- 212/15Primary Examinerwl-laryey C, Hornsby Attorney-Larson,Taylor'and wnzfiABSTRACT: A gantry crane inludes a framework supporting a main girderand a pair of swingable jibs which are movable I between a firstposition in' which they form anextension of the main girder and asecond, stowed position in which they are parallel to the main girder. Atrolley is mounted on rails pm- I vided on the girder and jibs. Astopper arrangement includes spring-loaded bolts which are displacedinto'thepath of the v trolley upon swinging of the jibs to the storedposition to prevent the trolley from running 05 the rails.

SAFETY BOLT The present invention relates to gantry cranes andespecially ship gantry cranes of the kind which are provided with jibs,said cranes having rails or guidances for a trolley.

Such cranes have the drawback that when the jibs are swung 'out forloading on for example port side of a ship, while the jibs on starboardside are swung in to parked position, one inadvertently can run thetrolley overboardon starboard side, if the crane operator is notattentive and stops the trolley in due time. To prevent such an accidenttheinvention proposes a special safety element.

ln accordance with the invention it is proposed a gantry crane of thekind mentioned above and so-arranged that it is provided with stoppermeans to prevent the trolley from being run out from that side of thejibs which are swung in, the stopper means automatically being effectivewhen the jibs move to swung-m position. I

In accordance with a preferred embodiment said stopper means consist ofspring-loaded bolts which by the swinging-in respective jib are movedinto the path of travel of the trolley.

To have a better understanding of the-invention it shall now bedescribed under reference to thepreferred embodiment 1 parked position.

Further it will be understood that even if such stopper means beingshown and described in connection with a gantry crane also other kindsof cranes or technical structures workgantry crane is seen in plane, itsmain girder l being provided with swingable jibs 2 which by convenienthinge connections 6 are secured to the ends of the main girder. Thegantry crane main girder is provided with rails 3 on which a trolley 4runs.

According to the invention stopper means are arranged for said trolleyconsisting of spring-loaded 7 bolts 5. These bolts are byconvenient-journaling in the main girder l axially dis placeable in adirection across the longitudinal direction of the main girder. Thelength of the bolts and their position is so adapted that when they areleft free their outer ends extend somewhat out 'from the main girders,while their inner ends are clear of the rails 3. The trolley 4 thusunobstructed can move on the rails 3.

When the jibs at the one end of the crane for instance the right jibs 2'in the drawing are swung in, they will strike against the outer ends ofthe bolts 5 and displace their inner ends against the spring loading toblock the rails 3 so that the trolley 4 is stopped. By simple, safe andsolid means it is thus provided an effective security againstinadvertently to run the trolley overboard from the one end of the cranewhere the jibs are in parked position.

I claim:

1. A gantry crane comprising a framework supporting a main girder, apair swingable jibs pivoted to each end of said main girder for swingingmovement between a first position in which the jibs form an extension ofsaid main girder, said main girder and jibs being provided with rails, atrolley mounted for movement along said rails, and a second positionwhere the jibs are stored substantially parallel to said main girder,said main girder and jibs being provided with rails, a trolley mountedfor movement along said rails, stopper means fixed to said main girdernear each end for preventing said trolley from inadvertently running offsaid rails at that side where the jibs are in said stored position, saidstopper means comprising spring-loaded bolts wherein the jibs uponswinging to said stored position engage said spring-loaded bolts todisplace said bolts into the path of movement of said trolley.

1. A gantry crane comprising a framework supporting a main girder, apair swingable jibs pivoted to each end of said main girder for swingingmovement between a first position in which the jibs form an extension ofsaid main girder, said main girder and jibs being provided with rails, atrolley mounted for movement along said rails, and a second positionwhere the jibs are stored substantially parallel to said main girder,said main girder and jibs being provided with rails, a trolley mountedfor movement along said rails, stopper means fixed to said main girdernear each end for preventing said trolley from inadvertently running offsaid rails at that side where the jibs are in said stored position, saidstopper means comprising spring-loaded bolts wherein the jibs uponswinging to said stored position engage said spring-loaded bolts todisplace said bolts into the path of movement of said trolley.